Fig. 3. Cuticle preparations of wild-type and T-Sp8 RNAi larval legs. (A-E) The joint between coxa and trochanter is easily identifiable by its heavy cuticularized structure (arrow). + indicates the presence of two bristles of different length (`mother and father') that are indicative for the coxa. The arrowhead indicates the tip of the pretarsal claw. (A) The leg of a wild-type first instar larvae is subdivided into the coxa (Cx), the trochanter (Tr), the femur (Fe), the tibiotarsus (Tita) and the pretarsal claw (Ptc). (B) Cuticle of a T Sp8^RNAi leg: weak phenotype. The coxa (Cx) is not affected; the segment distal to the coxa appears to be of mixed character. (C) Cuticle of a T-Sp8^RNAi leg: strong phenotype. The coxa is shorter than in the wild type, where the joint has developed partially. (D) Cuticle of a T-Sp8^RNAi leg: very strong phenotype; only part of the pretarsal claw present (arrowhead). (E) Cuticle of a T-Sp8^RNAi leg: very strong phenotype, no pretarsal claw present. Note that the coxa is also proximally shortened (C-E). (F) Cuticle of a larval head (wild-type) Lb: labium, arrowheads indicate the palps of the labium, the arrow indicates the telopodite (t) of the maxilla (Mx); e, endite of the maxilla. Ant, antenna; so, sense organ of the antennae; m, middle part; a, arista. (G) Effect of T-Sp8 RNAi on the head appendages. The asterisk marks the affected limbs: the distal palps of the labium are missing, the telopodite of the maxilla is strongly reduced. In weaker affected embryos, a reduction of the length has been observed (not shown). In the antenna, the middle segment is strongly reduced in size. No effect was seen in the mandibles. Only half of the head is shown in F,G.